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A262052
Euler pseudoprimes to base 5: composite integers such that abs(5^((n - 1)/2)) == 1 mod n.
16
217, 781, 1541, 1729, 5461, 5611, 6601, 7449, 7813, 11041, 12801, 13021, 13333, 14981, 15751, 15841, 16297, 21361, 23653, 24211, 25351, 29539, 30673, 38081, 40501, 41041, 44173, 44801, 46657, 47641, 48133, 53971, 56033, 67921, 75361, 79381, 90241, 98173, 100651, 102311
OFFSET
1,1
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000 (term 1..65 from Daniel Lignon)
MATHEMATICA
eulerPseudoQ[n_?PrimeQ, b_] = False; eulerPseudoQ[n_, b_] := Block[{p = PowerMod[b, (n - 1)/2, n]}, p == Mod[1, n] || p == Mod[-1, n]]; Select[2 Range[27000] + 1, eulerPseudoQ[#, 5] &] (* Michael De Vlieger, Sep 09 2015, after Jean-François Alcover at A006970 *)
PROG
(PARI) for(n=1, 1e5, if( Mod(5, (2*n+1))^n == 1 || Mod(5, (2*n+1))^n == 2*n && bigomega(2*n+1) != 1 , print1(2*n+1", "))); \\ Altug Alkan, Oct 11 2015
CROSSREFS
Cf. A006970 (base 2), A262051 (base 3), this sequence (base 5), A262053 (base 6), A262054 (base 7), A262055 (base 8).
Sequence in context: A019422 A231558 A101826 * A020251 A320715 A183778
KEYWORD
nonn
AUTHOR
Daniel Lignon, Sep 09 2015
STATUS
approved